B-cell chronic lymphocytic leukemia (CLL) is clinically a very heterogeneous disease with so far unclear pathogenesis. It ensues from the existing knowledge that it is a monoclonal expansion of B-lymphocytes that subsequently gather both in peripheral blood and in lymphatic organs, which further cause life-threatening complications in the form of enlargement of organs, a decreased function of immunity system, anaemia and others. It is supposed that the disease originates in the consequence of disturbance of apoptosis and changes in B lymphocytes migration. In 1975, a first prognostic system according to Rsi (Rai K R, Sawitsky A, Cronkite E P et al.: Clinical staging of chronic lymphocytic leukemia. Blood 1975 46: 219-234) was published and introduced, and subsequently in 1977 a similar classification of the disease according to Binet (Binet J L, Lepoprier M, Dighiero G et al.: A clinical staging system for chronic lymphocytic leukemia: prognostic significance. Cancer. 40, 855-64, 1977; Binet J L, Auquier A, Dighiero G et al.: A new prognostic classification of chronic lymphocytic leukemia derived from a multivariate survival analysis. Cancer 48:198-206, 1981) was introduced. Both systems are based on basic and clinically easy to observe features or available laboratory parameters (number and shape of lymphocytes, thrombocytes, values of haemoglobin, anaemia, infiltration of organs, etc.). In connection with modern molecular markers these systems are still used for the determination of prognosis.
With the introduction of cytogenetic methods, a correlation was observed between certain cytogenetic changes in the cells of patients and the development of their disease. For instance, deletions 17p and 11q are connected with a worse prognosis and, on the contrary, deletion 13q or trisomia of chromosome 12 are considered a positive prognostic feature. On the p arm of chromosome 17, there is located the tumour-suppressor gene p53 and the gene ATM (ataxia teleangiectasia mutated) is located on the q arm of chromosome 11. Both these genes act in the protection of the cell against damaging influences, therefore, their loss or mutation is connected with higher agressiveness of the disease. With regard to the fact that cytogenetic abnormalities occur in 75 to 80% of the patients, the examination by means of FISH probes panel has been included among standard examination procedures.
Another method available at present is the determination of the mutation status of the variable part of immunoglobulin chain by means of sequencing, and this method contributes significantly to the determination of the prognosis of the patients. It has been shown that the mutation status does not change during the disease. The patients with unmutated IgVH have a worse prognosis than those with the mutated one (Hamblin T J, Davis Z, Gardiner A et al.: Unmutated IgVH genes are associated with a more aggressive form of chronic lymphocytic leukemia. Blood 94, 1999, 1848-1854), wherein IgVH with less than 98% homology is considered to be mutated. The mutation status is a significant prognostic indicator regardless of the clinical stage at which the patients are. A significant improvement in the determination of the mutation status and subsequently of the prognosis of the patient was achieved by the recent identification of a molecular prognostic marker, cytoplasmatic protein ZAP-70 (Rosenwald A, Alizadeh A A, Widhopf G et al.: Relation of gene expression phenotype to immunoglobulin mutation genotype in B cell chronic lymphocytic leukemia. J Exp Med 194, 2001, 1639-1647), the high concentration of which correlates significantly with the unmutated IgVH status. Further developments leading to more accurate diagnosis include, e.g., the determination of expression of the surface molecule CD38 that is stable in time and the high expression of which is connected with a worse progression of the disease (Damle R N, Wasil T, Fais F et al.: IgV gene mutation status and CD38 expression as novel prognostic indicators in chronic lymphocytic leukemia. Blood 94, 1999, 1840-1847). Several prognostic markers are known, however, they have not been tested in a larger group of patients yet. A complex use of the above-mentioned analyses contributes significantly to the determination of the prognosis of the patients, however, so far no specific marker is known that would enable to identify with certainty the patients whose disease will prograde in near future and distinguish them from those patients who will remain at the clinical stage for many years without any need for therapy.
The aim of the present invention is to provide a method of determination of the diagnosis and/or prognosis which could replace the current diagnostic and prognostic methods by introducing new and specific markers that will enable the determination of the diagnosis and the prognosis on the basis of the diagnosis. Based on the determined diagnosis and prognosis, the most suitable treatment procedure for each individual patient is selected. The determination of the diagnosis and prognosis can easily be repeated in the course of the disease. Furthermore, the present invention can form a basis for the preparation of targeted therapy at several levels of cell signalization taking account of the current condition of a particular patient.